High (7.5) in mediawiki mediawiki. EPSS 1.1% chance of exploitation in the next 30 days.
An issue was discovered in the CasAuth extension for MediaWiki through 1.35.1. Due to improper username validation, it allowed user impersonation with trivial manipulations of certain characters within a given username. An ordinary user may be able to login as a "bureaucrat user" who has a similar username, as demonstrated by usernames that differ only in (1) bidirectional override symbols or (2) blank space.
Severity
CVSS 3.1
7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS
1.1% chance of exploitation in the next 30 days; higher than 65% of CVEs (scores of 2026-10-31)